"Please describe the attack. What did they look like?"
"Well one of them was very large, and the other rather skinny."
"Not the boys, the Dementors."
"Alright, right, well um, big. Cloaked. Then everything went cold, as though all the happiness had gone from the world."

-Amelia Bones, Arabella Figg &' Cornelius Fudge.